DTC C1243 BPMV Pump Motor Stalled. Chevrolet PJJ 2000

For 1990-2009 cars

### Circuit Description

The EBCM relay supplies power to the solenoid valves and pump motor. The EBCM relay activates when the ignition is turned to the ON position. Power is available to the solenoid valves and pump motor through the relay via the battery positive voltage circuit. The EBCM relay remains engaged until the ignition switch is turned to the OFF position or until the EBCM detects a malfunction which requires the system to be disabled.

### Conditions for Running the DTC

• | The pump motor is ON for at least 0.3 seconds.

• | The EBCM relay is ON.

### Conditions for Setting the DTC

The pump motor is stalled or turning slowly.

### Action Taken When the DTC Sets

The following actions occur:

• | The EBCM disables the ABS for the duration of the ignition cycle.

• | The ABS warning indicator turns ON.

• | A malfunction DTC is stored.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present and the scan tool Clear DTCs function is used.

• | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Diagnostic Aids

• | Possible causes for DTC C1243 to set are:

- | The pump motor has high resistance.

- | The pump motor is turning too slowly.

- | An internal EBCM malfunction exists.

• | The pump motor is an integral part of the BPMV and is not serviced separately.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This test verifies the operation of the pump motor.

2. This step tests the pump motor circuits of the BPMV for an open.

3. This step tests the pump motor and pump motor circuits by supplying power and ground.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | Go to ABS Diagnostic System Check

2

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With the scan tool, command the pump motor ON and OFF. This is done with the pump motor test located in ABS Special Functions.

Does the pump motor turn ON and OFF with each command?

--

Go to Testing for Intermittent and Poor Connections in Wiring Systems

Go to Step 3

3

1. Remove the EBCM from the BPMV. Refer to Electronic Brake Control Module Replacement.
2. Measure the resistance between the pump motor control circuits of the BPMV.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 4

Go to Step 6

4

1. Connect a 40 amp fused jumper between one control circuit of the BPMV and battery positive voltage.
2. Connect a 40 amp fused jumper between the other control circuit of the BPMV and ground.
3. Reverse the fused jumper connection on the control circuits of the BPMV

Does the motor run for either test?

--

Go to Step 5

Go to Step 6

5

1. Reconnect all components
2. Use the scan tool in order to clear the DTCs.
3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 7

Go to Testing for Intermittent and Poor Connections in Wiring Systems

6 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement. Did you complete the repair? | -- | Go to Step 8 | --
7 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement. Did you complete the repair? | -- | Go to Step 8 | --

8

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK